Former professional boxer and "The Hangover" actor Mike Tyson became a vegan because of a family history of obesity. He reportedly lost over 100 pounds after making the change.

Former professional boxer and "The Hangover" actor Mike Tyson became a vegan because of a family history of obesity. He reportedly lost over 100 pounds after making the change.

Photo: Frederick M. Brown, Getty Images

Former professional boxer and "The Hangover" actor Mike... Photo-4440069.59961 - Beaumont Enterprise

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After being diagnosed with the autoimmune disease Sjogren's Syndrome, professional tennis player Venus Williams switched to a raw, vegan diet. Her sister Serena Williams switched as well, for moral support.

After being diagnosed with the autoimmune disease Sjogren's Syndrome, professional tennis player Venus Williams switched to a raw, vegan diet. Her sister Serena Williams switched as well, for moral support.

Photo: Alberto E. Rodriguez, Getty Images

After being diagnosed with the autoimmune disease Sjogren's... Photo-4440070.59961 - Beaumont Enterprise

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Weird Al Yankovic has been a vegetarian (and sometimes vegan) since the 1990s.

Weird Al Yankovic has been a vegetarian (and sometimes vegan) since the 1990s.